1. Field of the Invention
The invention relates to the electrical contacting of insulated conductors by means of an insulation displacement contact. In particular, the invention relates to an insulation displacement contact and a contacting device with an insulation displacement contact.
2. Description of Related Art
For the electrical contacting of cable strands (insulated stranded cable conductors or wires), electrically conductive terminals are often used, which can be clamped onto and form an electrical contact with a contacting region of the conductor, which has been de-insulated in a previous step. In addition to these, insulation-piercing technologies are well known. These have to do with electrically conductive contacting elements, which are designed such that they can break through the electrical insulation at the contacting site and contact the underlying conductor without prior de-insulation. The best-known in this regard are the insulation displacement contacts (IDC), in which the cable strands are pressed between two blades in an area of the contact that is furnished with a bifurcated, bladed area, until the insulation is cut through, whereby not only is the conductor contacted, but the cable strand is also held fast at the same time. Also well known are the so-called piercing contacts, with which the insulation is punctured by at least one contacting point.
While the piercing contacts require a separate, independent cable strand holder, insulation displacement contacts are self-centering and have been widely tested and proven. The known insulation displacement contacts, as described for example in the introductory paragraph of U.S. Pat. No. 6,866,536, are however as a rule only appropriate for use with conductors that have a precise pre-defined diameter and a small range on either side of this diameter. In addition, they require a sizeable installation height and in most embodiments can only create a contact from one conductor to one other. Moreover, in general they are only appropriate for a single wiring of a conductor or at most only a very few wiring procedures, since they may be considerably plastically deformed when the cable strand is inserted between the blades. The extent of the plastic deformation depends in many cases upon how deeply the cable strand, and with it the conductor, is inserted between the blades of the IDC, so that the already limited degree of re-usability is also an unpredictable value.
An electrical terminal with an insulation displacement contact which is appropriate for the simultaneous contacting of two conductors is disclosed in DE 1990 98 25 or DE 20 2005 012 792 U. For this purpose, the insulation displacement contact is formed as a pincer-shaped (or dredging-shovel-like) curved insulation displacement contact (bended stamped piece), wherein the depth of the pincers created thereby (corresponding to the length of the curved insulation displacement contactor) is large enough to allow the inclusion of two conductors. This solution, thus, has the advantage that in contrast to conventional insulation displacement contacts, the spring force that is exerted on the conductor is not a function of the depth to which it is introduced; this first makes possible the simultaneous introduction of two equally thick (in cross section) conductors. However, it is disadvantageous that in this design a larger material strength is assumed, or the contact strength is relatively limited in relation to the overall size, and that the spring force is given by the thickness of the plate, and thus is a parameter that can only be manipulated—with little flexibility—through the thickness and selection of the material. Furthermore, the installation height of one of these insulation displacement contacts is relatively large, so that although it is appropriate for use in the terminal described in DE 20 2005 012 792 U, it is problematic when used with well-known plug systems. Furthermore, this design is not appropriate for the wiring of through-running cable strands.
EP 0 344 526 depicts a terminal block for a cable jack with a clip which is set into an insulating body. The clip exhibits on one side a terminal contact and on the other side a separation or clamping mechanism. In one embodiment, a bipartite connection piece connects proximally between the terminal contact and the V-shaped clamp mechanism to the terminal contact. The arrangement is however not appropriate for the introduction of an elastic spring force through the clamping mechanism such that a plastic deformation will occur during the insertion of a conductor. In addition, the clamps require a substantial installation height. Furthermore, due to the arising plastic deformation, they are in general only appropriate for a single wiring of a conductor or at the most only very few wiring procedures.